BlockOpResponseProto status = BlockOpResponseProto.parseFrom(
PBHelper.vintPrefixed(in));
checkSuccess(status, peer, block, file);
ReadOpChecksumInfoProto checksumInfo =
status.getReadOpChecksumInfo();
DataChecksum checksum = DataTransferProtoUtil.fromProto(
checksumInfo.getChecksum());
//Warning when we get CHECKSUM_NULL?
// Read the first chunk offset.
long firstChunkOffset = checksumInfo.getChunkOffset();
if ( firstChunkOffset < 0 || firstChunkOffset > startOffset ||
firstChunkOffset <= (startOffset - checksum.getBytesPerChecksum())) {
throw new IOException("BlockReader: error in first chunk offset (" +
firstChunkOffset + ") startOffset is " +
startOffset + " for file " + file);
}